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Observing the Surface Termination of LaScO3 Perovskite Using Solid-State Nuclear Magnetic Resonance
Tommy Yunpu Zhao1, Emily P Greenstein2, Ian L Peczak3
1Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States.
Journal of the American Chemical Society
|August 7, 2024
Summary
Surface-enhanced NMR spectroscopy reveals LaScO3 surfaces are hydroxyl-terminated with a ScO2 monolayer. This technique also identified previously undetected lanthanum defects, aiding in defect-free nanomaterial design.
Area of Science:
- Materials Science
- Surface Chemistry
- Nanotechnology
Background:
- Well-defined material surfaces are crucial for designing catalysts and nanomaterials.
- Understanding these surfaces is challenging due to polymorphism and dynamic restructuring.
Purpose of the Study:
- To introduce and demonstrate surface-enhanced NMR spectroscopy for characterizing complex material surfaces.
- To investigate the surface termination and potential defects of LaScO3.
Main Methods:
- Utilized double-resonance NMR experiments correlating surface oxygen and probe molecules to 139La and 45Sc nuclei.
- Performed surface-selective 17O and 45Sc NMR experiments.
- Conducted surface-selective 139La NMR experiments.
Main Results:
- Confirmed LaScO3 is terminated by a ScO2 monolayer.
- Showed the surface is hydroxyl-terminated and susceptible to restructuring upon moisture exposure.
- Detected previously unobserved surface lanthanum defects.
Conclusions:
- Surface-enhanced NMR spectroscopy is a powerful tool for detailed surface analysis.
- The findings provide insights into LaScO3 surface structure and dynamics.
- This technique can guide the synthesis of defect-free nanomaterials.
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